Once in awhile a friend will say "I want a tank like yours!" -- after about 10 minutes of describing the setup they've changed their minds. If they're OK with constant maintenance and work, the initial cost may not be much, but if they want an easy time of it, then you REALLY have to spend a lot initially (time and money). I can leave my tanks alone for a month at a time without any issues, but it wasn't easy to setup and extremely expensive.